Interfax said Monday that the military has put Bastion missile-launchers on duty in the Kaliningrad exclave that borders NATO members Poland and Lithuania. The Russian Defense Ministry said over the weekend that the Baltic Fleet was rearming itself with new missile-launchers, but didn't provide specifics.

The ministry had no immediate comment on the Interfax report.

The Bastion fires supersonic Oniks cruise missiles, which have a range of up to 450 kilometers (280 miles) and can be used against ships as well as ground targets. Last week, it made its combat debut in Syria where the Russian military used it against militants.

Separately, Viktor Ozerov, the head of the defense affairs committee in the Russian parliament's upper house, told RIA Novosti news agency Monday that Russia would also deploy Iskander tactical ballistic missiles and S-400 air defense missile systems to Kaliningrad in response to the U.S. missile defense plans.

"We are facing two main tasks — to penetrate air defenses and ensure protection from possible strikes," Ozerov said.

The S-400, which Russia has used to protect its air base in Syria, is a sophisticated system that can simultaneously track and strike multiple aerial targets at ranges of up to 400 kilometers (250 miles). Based in the Kaliningrad region, the S-400s will be capable of targeting NATO aircraft and missiles over most of the Baltic region.

Iskander has a range of up to 500 kilometers (310 miles) and high precision, allowing it to target facilities in several NATO member nations neighboring Russia with pinpoint accuracy. It can be fitted with a conventional or a nuclear warhead.

Last month, the deployment of Iskander missiles to the Kaliningrad region worried Russia's neighbors. The Russian military said the move was part of regular training, but didn't specify whether the missiles were sent there temporarily or deployed on a permanent basis.

The Kremlin long has warned that the development of NATO's U.S.-led missile defense system poses a danger to Russia's security and vowed to take countermeasures. Moscow also has complained strongly against the deployment of NATO's military units near Russia's borders.

"To counter these threats, we will be forced to strengthen our air and missile defenses in the western vector and to deploy additional means to defend the relevant command-and-control infrastructure," Ozerov told RIA Novosti.